Consumer baby monitors may get vital signs wrong

(Reuters Health) - Two popular monitors that promise to keep parents informed about their babies’ vital signs scored poorly in a test comparing them with actual hospital quality monitors, researchers say.

The commercially available monitors, which are not approved by the U.S. Food and Drug Administration, promise to sound an alarm via parents’ cell phones if the baby’s heart rate or blood oxygen levels move into danger zones, according to the study in JAMA.

Of the two monitors, the Owlet Smart Sock 2 performed better. But it still often sounded the alarm when there was nothing wrong and sometimes missed instances when blood oxygen levels were too low. The other monitor, the Baby Vida, performed even worse, completely missing unhealthy vital signs.

“There are lots of reasons parents should probably not be using consumer vital sign monitors,” said study leader Dr. Chris Bonafide of the Children’s Hospital of Philadelphia. “There is no evidence that these monitors prevent SIDS (sudden infant death syndrome). And the issues with accuracy . . . make me concerned that they could not just be unhelpful but that they could also create problems.”

Bonafide started wondering about commercially available monitors after treating a child brought to the emergency room because of a false alarm. To get a sense of how well the current generation of vital-signs monitors worked, he and his colleagues hooked 30 infants up to a hospital monitor on one foot and one of the consumer monitors on the other.

The Owlet device missed 9 occasions in which the baby’s oxygen saturation was alarmingly low, accurately caught low oxygen saturation 71 times and falsely sounded the alarm 26 times. The Baby Vida missed 102 occasions in which the baby’s oxygen saturation was too low, but it never sounded an alarm when nothing was wrong. It did, however, often falsely display low pulse rates.

Kurt Workman, co-founder and CEO of Owlet, noted in a statement emailed to Reuters Health that the most accurate method of assessing oxygen saturation involves testing blood that’s been drawn from an artery. “Owlet is designed for in-home use, with healthy babies while they sleep, to provide parents with information about their child’s well-being,” he said.

“Owlet sensor accuracy has been validated in studies performed by independent laboratories and when compared to arterial blood gas measurements the sensor performed well within international standards for pulse oximetry,” he added. “The accuracy and performance of the Owlet Smart Sock is something that we take very seriously.”

The manufacturer of the Baby Vida did not respond to a request for comment.

Bonafide worries that the devices might give parents a false sense of security when babies are truly sick. For example, he said, “take the parent who is watching a baby closely because the child has caught a cold or maybe is developing pneumonia. The parent might be concerned about how fast the baby is breathing but because the monitor falsely displays that the baby is OK when oxygen levels are dangerously low, that might reassure a parent who would otherwise have brought the child to the hospital for care. So instead of bringing the baby in that night, the parent might decide to wait till morning.”

There is also concern that false alarms will send parents rushing to the emergency room, said Dr. Thomas Diacovo, chief of newborn medicine at Magee-Womens Hospital and the Children’s Hospital of Pittsburgh at the University of Pittsburgh Medical Center.

Monitors in hospitals “have to meet stringent demands and are serviced every year,” said Diacovo, who was not involved in the new study.

One strength of the new study is that it “included a mixture of patients that were sick enough to be in the hospital,” said Dr. Gary Satou, director of pediatric echocardiography and co-director of fetal cardiology at the UCLA Mattel Children’s Hospital in Los Angeles. But it excluded infants who were very sick, Satou said.

The study shows that these consumer monitors “are not ready for prime time,” said Satou, who is not affiliated with the new research. “And even if an accurate device was available, the large majority of babies don’t need monitoring at home.”